Yappi

Motivation:

CPython standard distribution is coming with three profilers. cProfile, Profile and hotshot.
cProfile module is implemented as a C module based on lsprof, Profile is in pure Python and the
hotshot can be seen as a small subset of a cProfile. The motivation to implement a new profiler is
that all of these profilers lacks the support of multi-threaded programs. If you want to profile a
multi-threaded application, you must give an entry point to these profilers and then maybe merge
the outputs. None of these profilers is designed to work on long-running multi-threaded application.
While implementing a game server, it turns out that is is impossible to profile an application
retrieve the statistics then stop and then start later on on the fly(without affecting the profiled
application). With the experience of implementing a game server in Python, we have identified most
of the problems, tricky parts regarding profiler usage and so, we have come up with simple but
powerful requirements.